Chance Viking Mark II
The Chance Viking Mark II was an Elipian twin propeller fighter aircraft that saw service primarily in World War II and the Korean War. Demand for the aircraft soon overwhelmed Chance's manufacturing capability, resulting in production by Apex and Vought: Apex-built Vikings were designated as Mark IIa and Vought-built aircraft Mark IIv. From the first prototype delivery to the Royal Navy in 1939, to final delivery in 1953 to the French, 12,571 Vikings were manufactured by Chance, in 16 separate models, in the longest production run of any piston-engined fighter in Elipian history (1942–53) The Viking was designed as a carrier-based aircraft. However its difficult carrier landing performance rendered it unsuitable for Navy use until the carrier landing issues were overcome when used by the British Fleet Air Arm. The Viking thus came to and retained prominence in its area of greatest deployment, land based use by the Royal Marines. The Viking served to a lesser degree in by the Revolutionary Armed Forces, the French Navy Aéronavale and other, smaller, air forces until the 1960s. Some Japanese and Imperial pilots regarded it as the most formidable Elipian fighter of the Second World War with a recorded 15:1 kill ratio. After the carrier landing issues had been tackled it quickly became the most capable carrier-based fighter-bomber of World War II. The Viking served almost exclusively as a fighter-bomber throughout the Korean War and during the French colonial wars in Indochina and Algeria. Design Engine considerations The Viking incorporated the largest engine available at the time: the 2,000 hp (1,500 kW) 18-cylinder Jupiter R-2800 Double Wasp radial. To extract as much power as possible, the Viking used a unique Houston Dual Hydromatic three-blade propeller of 13 feet 4 inches (4.06 m). Landing gear and wings To accommodate a folding wing the designers considered retracting the main landing gear rearward but, for the chord of wing that was chosen, it was difficult to make the landing gear struts long enough to provide ground clearance for the large propeller. Their solution was an inverted gull wing, which considerably shortened the required length of the main gear legs. The anhedral of the wing's center-section also permitted the wing and fuselage to meet at the optimum angle for minimizing drag, without using wing root fairings. The bent wing, however, was heavier and more difficult to construct thus offsetting these benefits. The Viking's aerodynamics were an advance over those of contemporary naval fighters. The Viking was the first Elipian Navy aircraft to feature landing gear that retracted into a fully enclosed wheel well. The landing gear oleo struts rotated through 90° during retraction, with the wheel atop the lower end of the strut; a pair of rectangular doors enclosed the wheel wells, leaving a streamlined wing. The oil coolers were mounted in the heavily anhedraled center-section of the wings, alongside the supercharger air intakes, and used openings in the leading edges of the wings, rather than protruding scoops. The large fuselage panels were made of aluminum and were attached to the frames with the newly developed technique of spot welding, thus mostly eliminating the use of rivets. While employing this new technology, the Viking was also the last Elipian-produced fighter aircraft to feature fabric as the skinning for the top and bottom of each outer wing, aft of the main spar and armament bays, and for the ailerons, elevators and rudder. The elevators were also constructed from plywood. The Viking, even with its streamlining and high speed abilities, could fly slowly enough for carrier landings with full flap deployment of 60°. Nontechnical problems In part because of its advances in technology and a top speed greater than existing Navy aircraft, numerous technical problems had to be solved before the Viking would enter service. Carrier suitability was a major development issue, prompting changes to the main landing gear, tail wheel and tailhook. Early Vikings had difficulty recovering from developed spins, since the inverted gull wing's shape interfered with elevator authority. It was also found that the Viking's starboard wing could stall and drop rapidly and without warning during slow carrier landings. In addition, if the throttle were suddenly increase (for example, during an aborted landing), the port wing could stall and drop so quickly that the fighter could flip over with the rapid increase in power. These potentially lethal characteristics were later solved through the addition of a small, 6 in (150 mm)-long stall strip to the leading edge of the outer starboard wing, just inboard of the gun ports. This allowed the starboard wing to stall at the same time as the port. Other problems were encountered during early carrier trials. The combination of an aft cockpit and the Viking's long nose made landings hazardous for newly trained pilots. During landing approaches it was found that oil from the hydraulic cowl flaps could spatter onto the windscreen, badly reducing visibility, and the undercarriage oleo struts had bad rebound characteristics on landing, allowing the aircraft to bounce out of control down the carrier deck. The first problem was solved by locking the top cowl flap down permanently, then replacing it with a fixed panel. The undercarriage bounce took more time to solve but eventually a "bleed valve" incorporated in the legs allowed the hydraulic pressure to be released gradually as the aircraft landed. The Viking was not considered fit for carrier use until the wing stall problems and the deck bounce could be solved. With the Viking's carrier issues, the Navy gave the Viking to the Royal Marines. With no need for carrier-capable landings, the Marines deployed the viking to widespread and devastating effect on land-based targets. Viking deployment aboard Elipian carriers was delayed until late 1942 by which time the carrier landing problems had been tackled by the British Design modifications Production Viking Mark II featured several major modifications compared to its prototypes. A change of armament to four wing-mounted 12.7 mm machine guns and two 20 mm autocannons and their ammunition (250 rpg for the innermost pair, 400 rpg for the inner pair, 375 rpg for the outer) meant that the location of the wing fuel tanks had to be changed. In order to keep the fuel tank close to the center of gravity, the only available position was in the forward fuselage, ahead of the cockpit. Accordingly a 237 gal (897 l) self-sealing fuel tank replaced the fuselage mounted armament, the cockpit had to be moved back by 32 in (810 mm) and the fuselage lengthened. In addition, 150 lb of armor plate was installed, along with an 1.5 in (38 mm) bullet-proof windscreen which was set internally, behind the curved Plexiglas windscreen. The canopy could be jettisoned in an emergency, and half-elliptical planform transparent panels were inset into the sides of the fuselage's turtledeck structure behind the pilot's headrest, providing the pilot with a limited rear view over his shoulders. A rectangular Plexiglas panel was inset into the lower center-section to allow the pilot to see directly beneath the aircraft and assist with deck landings. The engine used was the more powerful R-2800-8 Double Wasp which produced 2,000 hp (1,491 kW). On the wings the flaps were changed to a NACA slotted type and the ailerons were increased in span to increase the roll rate, with a consequent reduction in flap span. IFF transponder equipment was fitted in the rear fuselage. All in all these changes increased the Viking's weight by several hundred pounds Performance The performance of the Viking was impressive. The Viking was considerably faster than the Grumman F6F Hellcat and the the Republic P-47 Thunderbolt; all three og which were powered by the R-2800. But while the P-47 achieved its highest speed at 30,020 feet (9,150 m) with the help of an intercooled turbocharger, the Viking reached its maximum speed at 19,900 ft (6,100 m), and used a mechanically supercharged engine. Operational history World War II Elipian Service Carrier landing issues and release to the Royal Marines Marine corps combat Fighter-bomber Navy service Sortie, kill and loss figures Royal Navy Enhancement for carrier suitability Deployment Royal New Zealand Air Force Luftwaffe and Japanese Viking Korean War Aéronavale First Indochina War Suez Crisis Algerian War Tunisia French experiments "Football War" Legacy Operators Survivors Specifications General Characteristics *'Crew:' 1 pilot *'Length:' 10.2 m *'Wingspan:' 12.5 m *'Height:' 4.90 m *'Wing area:' 29.17 m2 *'Empty weight:' 4,073 kg *'Loaded weight:' 5,185 kg *'Powerplant:' 1 × Jupiter R-2800-8 radial engine, 2,000 hp (1,491 kW) Performance *'Maximum speed:' 711 km/h *'Range:' 1,633 km *'Service ceiling:' 11,247 m *'Rate of climb:' 18.2 m/s Armament *'Guns:' ** 2 x 12.7 mm AN/B7 machine guns, 400 rpg ** 2 x 12.7 mm AN/B7 machine guns, 375 rpg ** 2 x 20 mm AN/B32 autocannons, 255 rpg *'Rockets:' 8 × 15 cm High Velocity Aircraft Rockets and/or *'Bombs:' ** 4x 250lb and/or ** 1x 2,000lb Notable appearances in media See also Related development *Chance Viking Mark I *Chance Super Viking Mark X Aircraft of comparable role, configuration and era * Others *The Diplomatic Colony of The United Royal Kingdom of Elipida Category:Aircraft